Multiple jammer localization and characterization based on time-frequency analysis

Jammers pose a threat to the reliability of satellite navigation systems. The vast majority of these devices generate broadband interference by rapidly sweeping wide bandwidths with continuous waves. Their waveforms fall into the set of nonstationary signals that can be conveniently analysed through timefrequency transforms. Based on a novel use of the S-transform, the present paper describes a framework for estimating the modulation characteristics of multiple jammers and therewith the respective locations. The performance are evaluated by means of numerical simulations for two jammers. When the jamming waveforms are well characterized, the locations of their sources can be estimated by trilateration with accuracies below ten meters within a square area of side of one kilometre.